hawk 336

Hi, I have a 2001 Firehawk with an LS1. I upgraded the air lid and MAF (85MM). Other than that the engine is stock. On April 19, I had Hardcore motorsports install an NX20118-10 system with 100hp jets, low fuel pressure switch and 1 heat range cooler NGK spark plugs. Hardcore filled the bottle to 26LB and I went to the track. My best et was 13.01 @ 105mph. I heard spark knock and the car was not running right with the nitrous armed. After 8 runs the bottle weighed 25.6 lb (I weighed it at the track). They said I lost a little when I opened the line. I had the hood open for about 15 minutes and decided to try again. 12.5 @ 111 mph and I could feel the hit. I only had two runs when I knew the nitrous was on (the other was at 12.6).

I wanted to rule out line blockage. I disconnected the air intake and armed the system Nitrous and gas blasted everywhere (perfect!).

Please help/

fotoboy

iTrader: (1)

Do you have a purge? If not and this was the first time on the juice you just needed to fill the line with the good stuff

00Vette

iTrader: (4)

I hate to say this, but your information isn't written well. I don't understand much of your scenario.

So were all of your runs N/A except the last two or where the 13 second and 12 second runs you spoke of the nitrous runs? What about the 8 runs?

Explain situation a little better and you'll get much more help! For example, which runs were on nitrous and what were the 60ft times, ET's, etc. Also give us info on which were nitrous runs and which were not. And if you could explain what you mean by "spark knock". I have never heard of it! Do you mean "knock retard"?

This will help us help you.

daniel6718

iTrader: (36)

the tps hit when the petal goes to the floor?

hawk 336

I really appreciate you input and questions!! This is the first time I've run the bottle on this car and I'm a bit confused.

I ran 12 times that night. The temp was cool (about 75 deg) and cloudy. The two runs when the spray came on were not back to back. After I came home I put the night together. It SEEMED like when I let the car cool down, the spray came on. My 60' times (when the car ran funny) ranged from 1.93 -2.0. When the spray came on 1.91 and 1.90.

Could the spark knock sound be caused by just the extra fuel being injected without nitrous? The low pressure switch is installed in the schrader (sp?) valve and I have no idea what that is set at. Could that be my problem?

hawk 336

Sorry I forgot... all the runs were with the nitrous "on." At wot the micro switch under the hood is being activated. I seem to have power to the system. I ohmed the low pressure switch and it has value.

2001z

iTrader: (32)

Sounds like maybe you need to setup that fuel pressure safty switch to me . Since that is the one thing that is always a problem . Just my .02 sine you said you have one on there . bypass it first and see how things work take a wire and jump it out .

NXZ28

iTrader: (45)

Check the relay for the nitrous system. Mine was doing the same thing at the track and I traced it back to a bad relay. BTW, the relay that went bad was new. I changed it to a better quality relay and I have not had any problems since.

00Vette

iTrader: (4)

So when the car cooled down you noticed that the spray DID spray?

That kind of leads me to beleive there may be some issue with your noid getting hot and sticking closed! Then again alot of people have had issues with there FPSS, which is what I think your calling the "low pressure switch". FWIW, I have my FPSS (fuel pressure safety switch) intalled directly off of the fuel rail end. I'm gathering that yours is basically the same if not exactly the same.........so the installation should be fine. However if its set incorrectly that may be the issue. You can bypass the fuel pressure safety switch by putting the wires from each side together on one side. That will bypass the FPSS and help you diagnose it in deed that is your problem.

I would start with that and if it still isn't working then go to the noids. I find it odd that your noids would only work when the car cooled down. If I remember correctly I have heard of this before. You might want to try to do a search and see who and what that's all about.